Incorporating Developmental Genetic Pathways into Speciation Theory

0075451强生和波特发展遗传学家在研究基因蓝图编码生物体特征的分子机制方面取得了巨大进展。基因经常在调节最终性状的途径中相互作用，这些相互作用通常涉及不同分子之间的结合。这一建议的作者约翰逊和波特博士已经将这些发育途径纳入了进化变化的模型中。他们启动了具有相同基因的计算机模拟种群对，并允许它们在相同的自然选择条件下进化。随着这些种群的进化，它们的杂交后代迅速积累了遗传不亲和性，因此变得非常不适合。作者还发展了分析理论来进行定量预测。仿真结果与理论预期相符。Johnson和Porter建议检验他们的模型对关于约束函数以及特征和适应度之间的关系的不同假设的稳健性。他们还将调查杂交不亲和性在多大程度上可以进化，尽管种群之间存在一些基因交换。这项研究对解决一个基本的进化问题--物种形成--具有重要意义。生物学家仍然对一个物种如何变成两个物种感兴趣，因为除了其他事情外，这个过程的知识对于理解生物多样性是如何产生的至关重要。杂交适应度降低是物种形成过程中的一个重要因素，通常是由于遗传不相容：一个物种的基因与另一个物种的基因不能很好地相互作用。这些不相容是如何进化的，人们仍然知之甚少，这在很大程度上是因为缺乏关于特征进化的机械模型。拟议的研究提供了这样一个看似合理的机制。此外，对发育遗传途径的基本进化原理的探索为群体遗传学和发育生物学的最终结合奠定了理论基础。

0075451 Johnson & PorterDevelopmental geneticists have made tremendous progress characterizing molecular mechanisms by which genetic blueprints encode the traits of organisms. Genes often interact in pathways to regulate the final traits, and these interactions usually involve binding between different molecules. Drs. Johnson and Porter, the authors of this proposal, have incorporated these developmental pathways into models of evolutionary change. They started pairs of computer-simulated populations with identical genes and allowed them to evolve under identical conditions of natural selection. As these populations evolved, their hybrids quickly accumulated genetic incompatibilities and thus became drastically less fit. The authors have also developed analytical theory to make quantitative predictions. The simulation results fit the theoretical expectations. Johnson and Porter propose to examine the robustness of their models to different assumptions about binding functions and the relationship between traits and fitness. They will also investigate the extent to which hybrid incompatibilities can evolve despite some exchange of genes between the populations. This study has important implications for the solution to a fundamental evolutionary problem: species formation. Biologists remain interested in how one species become two because, among other things, knowledge of this process is critical for understanding how biodiversity is generated. Hybrid fitness reduction, an important contributor to the speciation process, usually is due to genetic incompatibilities: genes from one species do not interact well with genes of the other. How these incompatibilities evolve is still poorly understood, in large part because mechanistic models of how traits evolve are lacking. The proposed study provides such a plausible mechanism. Moreover, the proposed exploration of the basic evolutionary principles of developmental genetic pathways establishes a theoretical foundation for the ultimate union of population genetics and developmental biology.